


Comets and Conversation

by Messier42



Category: Doctor Who, Doctor Who (2005)
Genre: Astronomy, Science
Language: English
Status: Completed
Published: 2020-07-16
Updated: 2020-07-16
Packaged: 2021-03-04 22:21:21
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,328
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/25293850
Author URL: https://archiveofourown.org/users/Messier42/pseuds/Messier42
Summary: The Doctor takes the fam to see a comet. Essentially just an excuse to write about astronomy, I won’t lie.
Kudos: 5





	Comets and Conversation

**Author's Note:**

> Everything written here is proper science! If you’d like to see the comet yourself (it’s possibly a once-in-a-lifetime thing so please do consider it), you can search online for instructions based on your location. Just think, you might even spot the TARDIS while you’re out looking!

“Comet C/2020 F3 Neowise!” the Doctor proclaimed, throwing open the TARDIS doors with a flourish. “Ta dah!” 

She started grabbing pillows and blankets from a bemused-looking Yaz, forming a nest of sorts in the doorway. Outside, the Earth stretched out below them, a vast but tiny marble hung against the backdrop of space. 

“It’s about time I taught you all some astronomy. What use is it me telling you directions to the places you visit, if you don’t know your Altair from your Aldebaran?” she continued. 

“Hey!” said Yaz indignantly. “I know some astronomy! Me and my Dad used to go out looking for the crescent Moon at Ramadan and Eid. Not that we were ever any good at it mind you — we usually had to find out if it had been seen from his mates at the mosque. Plus we did the constellations and that at school.” 

“And how relevant to us is it actually though, Doc?” Graham replied with a bit of a huff. “It’s not like I’m ever going to have to divert the X78 bus to Doncaster via Jupiter, at least I hope not.” 

“You wouldn’t even be able to drive on Jupiter” Ryan piped up. “It’s one of them gas giants isn’t it? We did do that in school too.” 

The Doctor looked exasperated. “10 points to Ryan and Yaz! And minus three to Graham for a lack of enthusiasm. Honestly, I’m trying to show you the wonders of the universe, and you moan about a little scientific exposition.” 

Yaz had already settled down on a pillow by the door. She was gazing out at the sight in front of her: a wispy tail streaming out from a brighter core, just peaking out above the blueish glow of the edge of the Earth. Yellow, white, and orange glows drew outlines of the dark continents below. 

“Come on guys, it’s actually a pretty decent view. Is that the comet there? It’s beautiful.” Yaz said. 

The Doctor did a little flourish with her hands and grinned her big, toothy smile. “Thank you Yaz! Best seats in the house, that’s what I can give you. Yaz, Ryan, this is the first great Northern hemisphere comet of your lifetimes. It was only discovered in March 2020, and by July it’s so bright that you can see it with the unaided eye. Graham, did you ever see Hale-Bopp when it popped by in the 90s? Or Halley’s Comet in 1986? Had a liiittle bit of a run-in with some old friends, well, enemies for that one so I never got to appreciate it properly.” 

“Yeah I think I had a peep at them.” Graham responded. “Didn’t get as good a view as this though!” 

“Hmm, and with that you’ve earned your points back. Come on, let’s settle in for a bit — plenty of room!” the Doctor said. 

They all just about fit in the doorway after a bit of shifting around and elbow poking. Ryan looked a little hesitant at being so close to the edge, but a quick squeeze on the shoulder from Graham reassured him. The Doctor reached into her pockets and pulled out four pairs of ridiculous looking goggles. 

“Binoccuglasses!” she said excitedly. “All the rage in 22nd century astronomy. Auto-focus, adjustable aperture, plus infrared and ultraviolet capabilities. Have a play around with them.”

Whilst they fiddled around with the goggles, the Doctor launched into information mode. 

“Really, this is the best way to view a comet — up away from atmospheric distortions and light pollution. But you’d be able to see it from Sheffield too if you wanted. It’s bright enough to be seen, even in the middle of a city! You’d get a better view heading out into the Peak District too. Oooh or even better, the North York Moors or the Dales. Anywhere with a dark northern sky.”

She paused for a moment, shifting slightly in the doorway. Yaz couldn’t tell if she had stopped to catch her breath, or if she didn’t need to and had done so anyway in order to appear slightly more normal. 

The Doctor continued. “The comet is circumpolar if you’re far enough north. You ever see those long exposure photographs with the star trails going around in a circle? They’re brilliant photos they are. Anyway, it’s like that — the comet doesn’t rise and set; it’s in the sky for as long as it’s dark enough.” 

“But what actually is it?” asked Ryan. “Like, what’s it made of? Is it like an asteroid?” 

The Doctor beamed. “Great question! Asteroids and comets are both small solar system objects, but they’re otherwise quite different. Asteroids are just rocks, and in general stay within fairly regular orbits. Most of them are between Mars and Jupiter, in the asteroid belt, but it’s really not as dense as films would have you believe. You could fly right though the belt and not see another asteroid. Space is really, _really_ big and mostly empty. Anyway, the main thing is that they’re inactive lumpy space rocks. Well, other than the ones with Sycorax or fire-breathing munchkins on them but I won’t go into that. Remember I showed you the one named after Rosa Parks?” 

The gang nodded in agreement, and the Doctor continued. 

“Comets, on the other hand, have a bit more going on. They come from much further out in the Solar System in highly elongated orbits that can be thousands of years long. They’re sometimes called _dirty snowballs_ ; they’re a mix of rock, dust, and ice, plus a few other things. When their orbits bring them closer into the Sun, the ice starts to sublimate — that’s just a fancy word to say it goes straight from being solid to gas. They’re actually quite dark normally, what’s called having a low _albedo_ , because they don’t reflect much sunlight. Anyway, when the comet warms up near the Sun, something called a coma forms around it like an atmosphere. That’s what makes it look fuzzy. As the comet travels it leaves a tail of dust. And some are just spectacular. Just look at it!” she finished, exclaiming gleefully. 

“Okay, I’ve got to hand it to you Doc,” Graham admitted. “It’s actually pretty good.”

They sat there in silence for a little while, admiring the beauty. For all the joy of seeing the Universe and all of its glory, there was something special for them to see their home planet laid out beneath them. Even the Doctor couldn’t help but keep looking down; at this point it was practically her second home. 

“I bet Nan would’ve loved this”, Ryan eventually said quietly. 

Graham gave him a small smile in response. “Yeah, she would’ve, wouldn’t she? She’d be happy that we’re out here, getting to see it all though.”

They all sat in companionable silence for a while longer. Suddenly, the Doctor sprung up, unable to contain her itchy feet any longer. 

“Right then! That’s enough astronomy for one day. Not that I want to make a curriculum out of this, but who fancies a bit of PE? I could take you for a hike through the mountains of Kaldor? Oooh, or a swim on a leisure planet? Or, just set the controls to random seeing as we’ll probably end up running anyway. Actually yeah, let’s do that. Sound good?”

With nods of approval, she closed the doors and set off around the TARDIS console, fingers dancing across the controls. 

“And if we’re really lucky, we’ll bump into Albert Einstein or Katherine Johnson or Plineeteo the Third dash alpha. Can’t go wrong with a bit of maths!” 

She seemed a lot more enthusiastic about the prospect than her companions, but they didn’t mind too much. The Doctor could make anything interesting, no matter how boring they’d found it at school. How could they be bored with the whole universe at their fingertips? There was so much out there to see, and astronomy was only just the beginning.

**Author's Note:**

> If you’re in the UK, take a peak outside anywhere between 11pm-3am. If it’s clear, you might be able to spot a fuzzy blob low in the northern sky — that’s the comet! It’s even better in binoculars. Elsewhere in the world, you’ll be able to look up specifics for your location. Happy stargazing. :)


End file.
